Blastesthia turionella

Author: (Linnaeus, 1758)

Pine bud moth

Species Overview:

Adult: 14-21 mm wingspan; labial palpus, head, thorax anteriorly and basal two-thirds of tegula pale ochreous-orange; forewing ground colour silvery white, diffusely strigulated with dark grey; markings orange-brown with an admixture of grey. In males hindwing white, suffused with fuscous in apical third; hindwing usually more extensively infuscate in females.
Egg: deposited singly on the innerside of the needles near the needle sheath.
Larva: 9-10 mm long; head black; prothoracic plate blackish brown or black; abdomen light brown or yellowish brown, darker dorsally, the dark pigmentation often forming two diffuse transverse bands on the segments; integument and prothoracic plate finely shagreened; pinacula inconspicuous; anal plate dark grey or brown. Ventral prolegs with 18-21 crochets.
Pupa: dark brown, abdomen yellowish ventrally; anal segment with 4 hooked bristles dorsally and 2 pairs of hooked bristles ventrally; frons rounded, smooth, without processes; intersegmental cuticle without spines [details pupa B. turionella ] . Pupa spun up in the larval habitation.

Taxonomic Description:

Male:

Blastesthia turionella male
Blastesthia turionella adults
External characters: Wingspan 14-21 mm. Labial palpus, head, thorax anteriorly and basal two-thirds of tegula pale ochreous-orange, thorax posteriorly and tip of tegula grey. Forewing with termen a little oblique, straight and rounded at tornus, without costal fold; ground colour silvery white, diffusely strigulated with dark grey, an admixture of orange-brown medially; markings orange-brown with a variable admixture of grey; basal and sub-basal fasciae usually poorly developed and reduced to transverse fuscous striae, but sub-basal fascia sometimes better defined; median fascia obsolescent dorsally, well developed on costa, oblique to above middle and confluent with a large, vertical pre-tornal marking; subterminal fascia arising from near tornus, dilated in apical area, confluent with an apical spot and medially with pre-tornal marking; cilia grey, with a blackish sub-basal line. Hindwing white, coarsely suffused with fuscous in apical third and along termen, sometimes with an ochreous admixture towards apex; cilia white, with a grey sub-basal line (Bradley et al., 1979).

male genitalia B. turionella
Genitalia: Uncus reduced; gnathos absent; socii very long and narrow, curved outwards. Valva with clasper and semicircular notch on ventral margin. Cucullus slightly broader than in Blastesthia posticana.

Female:

External characters: Similar to male, but hindwing usually more extensively infuscate.

female genitalia B. turionella
Genitalia: Sterigma cylindrical. Cingulum large; signum not sharply pointed.

Variation:

Minor variation is found in the forewing colouration and markings, especially in the development of the fasciae.

Biology:

Blastesthia turionella occurs in mountains up to 1200 m above sea level. The species tends to reach epidemic levels in flat country only. The bionomics concern only these areas. Adults emerge in warm areas between the middle of April and the beginning of May. Males emerge 3-5 days before the females do. The flight period lasts 4-6 weeks. Eggs are deposited singly on the innerside of the needles near the needle sheath. The neonate larvae appear in 2 -3 weeks. They crawl towards the fresh shoots, chew themselves into the base of a needle pair that has just emerged from the sheath and excavate this and a few neighbouring needle pairs. The third instar larva bores itself into a side bud of a newly formed whorl of buds, which are fed empty. Until late autumn, one or more other buds and finally the middle bud are excavated. The larva attaches at the feeding site a dense, white silken tunnel in which it hibernates as prepupa. Pupation follows after the middle of March; the pupal stage lasts about 3 weeks (Bogensch├╝tz, 1991).

Host plants:

Pinus sylvestris, Pinus mugo (species complex), Pinus nigra and Pinus contorta; also recorded from Abies alba.

Damage:

Outbreaks of Blastesthia turionella usually occur on large-scale monocultures of pine trees in flat country. Especially 5-12 year old pine trees are damaged when a simultaneous attack by Rhyacionia buoliana occurs. Economic damage is reported from North-Western Europe, Germany, Czech Republic and Poland. At high population densities all buds in the upper parts of the crown are destroyed. The formation of adventive shoots causes bushy growth and thus decreased length growth. Loss of needles by the feeding of the young larvae may lead to death of the trees.

Distribution:

Europe to Eastern Russia and Japan.

Pheromone:

Pheromone unknown.

Attractantia:

E 9-12Ac (Booij and Voerman, 1984a)

Parasitoids:

Macrocentrus abdominalis Fabricius (Braconidae)
Macrocentrus infirmus Nees (Braconidae)
Macrocentrus resinellae (Linnaeus) (Braconidae)
Ephialtes longiseta Ratz. (Ichneumonidae)
Ephialtes roborator Fabricius (Ichneumonidae)
Ephialtes ruficollis Grav. (Ichneumonidae)
Ephialtes sagax Htg. (Ichneumonidae)
Ephialtes terebrans Ratz. (Ichneumonidae)
Pimpla sp. (Ichneumonidae)
Lissonota carbonaria Hlmg. (Ichneumonidae)
Lissonota transversa Bridgm. (Ichneumonidae)
Glypta resinanae Hartig (Ichneumonidae)
Campoplex rufifemur Thoms. (Ichneumonidae)
Trophocampa dubia Tschek. (Ichneumonidae)
Orthocentrus anamelus Grav. (Ichneumonidae)
Elasmus scimitscheki Fahr. (Elasmidae)
Tetrastichus turionum Htg. (Eulophidae)
Habrocytus turionum Fahr. (Pteromalidae)



Blastesthia mughiana Zeller

Blastesthia mughiana adult
Blastesthia mughiana Zeller resembles Blastesthia turionella, but the forewings are much darker. Blastesthia mughiana is an alpine species: it occurs in the Alps between 1450 and 2000 m, feeding on Pinus cembra and Pinus mugo.

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